<template>
  <div class="pagination">
    <!-- 上一页 -->
    <button :disabled="pageNo == 1" @click="$emit('getPageNo', pageNo - 1)">
      <
    </button>
    <button
      v-if="startNumAndEndNum.start > 1"
      @click="$emit('getPageNo', 1)"
      :class="{ active: pageNo == 1 }"
    >
      1
    </button>
    <button v-if="startNumAndEndNum.start > 2">···</button>
    <!-- 中间部分 -->
    <!-- eslint-disable-next-line vue/no-use-v-if-with-v-for -->
    <button v-for="(page, index) in startNumAndEndNum.end" :key="index" v-if="page >= startNumAndEndNum.start" @click="$emit('getPageNo', page)" :class="{ active: pageNo == page }">
      {{ page }}
    </button>

    <!-- 下一页  -->
    <button v-if="startNumAndEndNum.end < totalPage - 1">···</button>
    <button
      v-if="startNumAndEndNum.end < totalPage"
      @click="$emit('getPageNo', totalPage)"
      :class="{ active: pageNo == totalPage }"
    >
      {{ totalPage }}
    </button>
    <button
      :disabled="pageNo == totalPage"
      @click="$emit('getPageNo', pageNo + 1)"
    >
      >
    </button>
    <button style="margin-left: 30px">共 {{ total }} 条</button>
 </div>
</template>

<script>
export default {
  // eslint-disable-next-line vue/multi-word-component-names
  name: 'Pagination',
  props: ['pageNo', 'pageSize', 'total', 'continues'],
  computed: {
    // 计算一共有多少页,用总的页数/每页展示的数据量，因为结果可能为小数，所有这里向上取整
    totalPage() {
      return Math.ceil(this.total / this.pageSize);
    },
    //计算出连续的页码的起始数字与结束数字[连续页码的数字:至少是3]
    startNumAndEndNum() {
      const { continues, pageNo, totalPage } = this
      //先定义两个变量存储起始数字与结束数字
      let start = 0,
        end = 0
      //连续页码数字3【就是至少3页】，如果出现不正常的现象【就是不够3页】
      //不正常现象【总页数没有连续页码多】
      if (continues > totalPage) {
        start = 1
        end = totalPage
      } else {
        //正常现象【连续页码3，但是你的总页数一定是大于3的】
        //起始数字
        start = pageNo - parseInt(continues / 2)
        //结束数字
        end = pageNo + parseInt(continues / 2)
        //把出现不正常的现象【start数字出现0|负数】纠正
        if (start < 1) {
          start = 1
          end = continues
        }
        //把出现不正常的现象[end数字大于总页码]纠正
        if (end > totalPage) {
          end = totalPage
          start = totalPage - continues + 1
        }
      }
      return { start, end }
    }
  }
}
</script>

<style lang="scss" scoped>
.pagination {
  // height: 100%;
  display: flex;
  justify-content: flex-end;
  align-items: flex-end;
  button {
    margin: 0 5rpx;
    color: #ffffff;
    outline: none;
    border-radius: 1rpx;
    padding: 0 3rpx;
    vertical-align: top;
    display: inline-block;
    min-width: 35rpx;
    height: 35rpx;
    line-height: 35rpx;
    cursor: pointer;
    box-sizing: border-box;
    text-align: center;
    border: 0;
	border: 1px solid #0284F1;
	background: RGBA(215, 238, 247, 1);
	font-size: 20rpx;
	font-family: PingFangSC-Regular, PingFang SC;
	font-weight: 400;
	color: rgba(51, 51, 51, 1);
	
    &[disabled] {
      color: #c0c4cc;
      cursor: not-allowed;
	  
    }

    &.active {
      cursor: not-allowed;
      background-color: #409eff;
      color: #fff;
    }
  }
}
.active {
  background: skyblue;
}
</style>
<style>
	uni-button:after {
		border: none;
	}
</style>
